Vulnerability · Published Feb 26, 2021 · Assigned by mozilla
CVE-2021-23973
Medium 6.5
In plain English
A medium-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.4% (higher than 72% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)1.4%top 28.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted, and the content of that error may have revealed information about the resource. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.21 | firefox | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.22 | firefox | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.23 | firefox | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.20 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.21 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.22 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.23 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.21 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.22 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.23 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.24 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.20 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.21 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.22 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23973 |
| Alpine:v3.23 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23973 |
| Debian:12 | firefox-esr | 78.8.0esr-1 | DEBIAN-CVE-2021-23973 |
| Debian:13 | firefox-esr | 78.8.0esr-1 | DEBIAN-CVE-2021-23973 |
| Debian:14 | firefox-esr | 78.8.0esr-1 | DEBIAN-CVE-2021-23973 |
| Debian:12 | thunderbird | 1:78.8.0-1 | DEBIAN-CVE-2021-23973 |
| Debian:13 | thunderbird | 1:78.8.0-1 | DEBIAN-CVE-2021-23973 |
| Debian:14 | thunderbird | 1:78.8.0-1 | DEBIAN-CVE-2021-23973 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2021-23973 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 86 |
| Mozilla | Thunderbird | < 78.8 |
| Mozilla | Firefox ESR | < 78.8 |
References
- https://www.mozilla.org/security/advisories/mfsa2021-07/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-09/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-08/ x_refsource_MISC
- https://bugzilla.mozilla.org/show_bug.cgi?id=1690976 x_refsource_MISC
- [debian-lts-announce] 20210301 [SECURITY] [DLA 2578-1] thunderbird security update mailing-list, x_refsource_MLIST
- DSA-4866 vendor-advisory, x_refsource_DEBIAN
- GLSA-202104-10 vendor-advisory, x_refsource_GENTOO
- GLSA-202104-09 vendor-advisory, x_refsource_GENTOO